Sensorless control of permanent magnet synchronous motors

The permanent magnet synchronous motors (PMSM), which is widely used in industrial applications in recent years, require stator and rotor fields to be synchronised in order to get a smooth torque. This is maintained by position sensors. These sensors increase the system coast and dimension and decrease the reliability. Hence, the elimination of sensors from the system is very important.There are so many methods for position and speed sensorless control of PMSM. But these methods change according to different types of PMSM and their working speed. Many of these methods use motor?s mathematical model. Motor?s mathematical model which is used position and speed sensorless control is very important. Nevertheless, Most of position and speed sensorless control methods do not give a good result at the low speeds. V/f position and speed sensorless control of PMSM is seen attractive at the wide speed rages.In this thesis, the analysis of PMSM has been done using finite element method to obtain better motor model. Firstly, this model has been used in the vector control of PMSM with position and speed sensor. Secondly, the model has been used position and speed sensorless control of PMSM. Cylindrical and salient pole motor have been used in the finite element method and in the motor model. Fuzzy Logic Controller has been used for the position and speed sensorless V/f control method with wide speed range. Finally, the study has been simulated using MATLAB Simulink. Real time implementation is realized using DSpace 1104 Controller.Keywords: Permanent Magnet Synchronous Motor (PMSM), Finite Element Method, Vector Control, Position and Speed Sensorless Control, Fuzzy Logic Controller (FLC).